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Ngoclinhk6
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Nguyễn Lê Phước Thịnh
18 tháng 2 2021 lúc 22:11

1) Vì x=25 thỏa mãn ĐKXĐ nên Thay x=25 vào biểu thức \(A=\dfrac{\sqrt{x}-2}{x+1}\), ta được:

\(A=\dfrac{\sqrt{25}-2}{25+1}=\dfrac{5-2}{25+1}=\dfrac{3}{26}\)

Vậy: Khi x=25 thì \(A=\dfrac{3}{26}\)

2) Ta có: \(B=\dfrac{\sqrt{x}-3}{\sqrt{x}+1}+\dfrac{2x+8\sqrt{x}-6}{x-\sqrt{x}-2}\)

\(=\dfrac{\left(\sqrt{x}-3\right)\left(\sqrt{x}-2\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}+\dfrac{2x+8\sqrt{x}-6}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)

\(=\dfrac{x-5\sqrt{x}+6+2x+8\sqrt{x}-6}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)

\(=\dfrac{3x+3\sqrt{x}}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)

\(=\dfrac{3\sqrt{x}\left(\sqrt{x}+1\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)

\(=\dfrac{3\sqrt{x}}{\sqrt{x}-2}\)

Nguyễn Xuân Thành
11 tháng 5 2021 lúc 14:57

câu 3 chứ

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Ngoclinhk6
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Đặng Hữu Trang
16 tháng 7 2021 lúc 17:04
ext-9bosssssssssssssssss
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Ánh Mạch
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Nguyễn Lê Phước Thịnh
15 tháng 10 2021 lúc 21:36

a: \(\left|\overrightarrow{AB}-\overrightarrow{AC}\right|=\left|\overrightarrow{CB}\right|=10a\)

b: \(\left|\overrightarrow{AB}+\overrightarrow{AC}\right|=\dfrac{BC}{2}=5a\)

Thanh Tuyền
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Khinh Yên
9 tháng 9 2021 lúc 11:17

Refer

1. “Your cousin speaks English very well” Paul told me

Paul said that ___________my cousin spoke English very well____________

2. “The man broke out of prison yesterday” said the policeman

The policeman told us_that the man had broken out of prison the day beforr__

3. “I’ll lend you this book as soon as I finish it” Owen said to me

Owen said __me that he would lend me that book as soon as he finished it___

4. “I think I forgot to turn off the lights this morning” Brenda told Brian

Brenda told Brian ____that he thought he had forgotten to turn off the lights that morning.____

5. “I work eight hours a day, except when the children are on holiday” said Mrs. Wood

Mrs. Wood said me that he worked eight hours a day, excepted when the children were on holiday

6. “You’ve been making good progress this semester” Miss Lynn told me

Miss Lynn said that _____I had been making good progress that semester_________

7. “If you bought all the tickets, you would win the lottery” the man said

The man told me ______that If I had bought all the tickets, I would win the lottery______________

8. “I like swimming but I don’t go very often” Jill said to Pam

Jill said that ______he liked swimming but he didn’t go very often___________________________

9. “I want to buy it, but I haven’t brought any money” said Patrick

Patrick told me _________that he wanted to buy it, but he hadn’t brought any money_______________________

10. “I’m going to visit my aunt in Hue, but I’m not sure when” said Mai

Mai told me _________that she was going to visit her aunt in Hue, but she was not sure when__________________

Thanh Hiền Đặng
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Ánh Mạch
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Nguyễn Lê Phước Thịnh
1 tháng 11 2021 lúc 23:19

Câu 1: Vì (d') vuông góc với (d) nên \(a\cdot\dfrac{-1}{3}=-1\)

hay a=3

Vậy: (d'): y=3x+b

Thay x=4 và y=-5 vào (d'), ta được:

b+12=-5

hay b=-17

Thượng Nguyễn
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Phạm Vĩnh Linh
9 tháng 8 2021 lúc 14:59

1, What would he like to have for breakfast?

He would like to have a sandwich

2,Who would you like to go fishing with?

I would like to go fishing with my father

3,What would her children like to do in the summer?

They would like to go swimming

4,When would Mrs Tam like to go shopping?

She would like to go shopping at weekends

5,Where would Hung and Tung like to study

They would like to study in the library

Đỗ Thanh Hải
9 tháng 8 2021 lúc 15:01

1 What would he like for breakfast? 

He'd like a sandwich

2 Who would you like to go fishing with?

I would like to go with my father

3 What would her children like to do in summer?

They would like to swim inpool

4 When would Mrs Tam like to go shopping?

She would like to go shopping on the weekends

5 Where would Tung and Hung like to study ?

THey would like to study in the school library

Nguyễn Dược Tiên
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em ơi chưa có bài em nhé, em chưa tải bài lên lám sao mình giúp được 

Nguyễn Dược Tiên
3 tháng 3 2023 lúc 22:37

Dạ đề đây ạ loading...  

Nguyễn Dược Tiên
3 tháng 3 2023 lúc 22:47

Dạ đề đây ạloading...  

Bac Tran
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Hương
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Nguyễn Lê Phước Thịnh
22 tháng 2 2021 lúc 20:10

a) Phương trình hoành độ giao điểm là: 

\(x^2=\left(m+2\right)x-2m\)

\(\Leftrightarrow x^2-\left(m+2\right)x+2m=0\)

\(\Delta=\left(m+2\right)^2-8m=m^2+4m+4-8m=m^2-4m+4=\left(m-2\right)^2\)

Để (d) và (P) cắt nhau tại hai điểm phân biệt thì \(\Delta>0\)

\(\Leftrightarrow\left(m-2\right)^2>0\)

mà \(\left(m-2\right)^2\ge0\)

nên \(m-2\ne0\)

hay \(m\ne2\)

Vậy: Để (d) và (P) cắt nhau tại hai điểm phân biệt thì \(m\ne2\)